Practical Pearls: Broken Hearts or Broken Bones?

The primary health care of women is a complex world of "Hearts, Hormones, Ovaries, Breasts and Bones." Over the past year women have expressed concern when reading articles and listening to media reports that suggest taking calcium supplements may help prevent fractures but at the same time may increase their risk for cardiovascular events. The Nurses' Health Study reported calcium supplement intake increased from 30% in 1984 to 72% in 2004. What is the evidence to bring to bear on this conundrum?

The calcium subcommittee of the Professional Practice Committee of the American Society of Bone and Mineral Research (ASBMR) suggested a potential link between calcium supplements and an increase in endpoints of MI, stroke and sudden death. Does this mean we must evaluate a patient's calcium intake as a risk factor for CVD? The prospective studies, thus far, have been of short duration. Many senior citizens share a number of risk factors for both CVD and osteoporosis. So what's a woman, and confused public, to do - break a bone or have a broken heart?

Calcium is an essential mineral for cell physiology. It is the fifth most abundant element in our body and impacts cardiac function, vascular tone, the coagulation system, and the nervous system. It is also a key structural component of our bones and teeth. Current daily recommendations for bone health include calcium intake of 1200 mg and vitamin D intakes of 600-800 IU for women over 50. There are no guidelines related to calcium supplements specific to vascular diseases. It has been suggested that a link between calcium supplements and CVD could be related to if the calcified plaques are the response to injury of the vascular walls. The assessment of patients' cardiovascular risks and evaluation of their bone status are both essential for comprehensive healthcare. We must review our patients' nutritional status to coordinate health care guidelines.

There are dietary guidelines to reduce cardiac risk, but the American diet is also a major risk for osteoporosis. Typical food choices produce a metabolic imbalance that decreases absorption and retention of minerals like calcium. Diets that include excess protein, high-fat dairy products, sugars, carbonated soft drinks, alcohol, caffeine, and fried foods all produce an acidifying effect that causes calcium to leave the bones in an attempt to buffer this acidity. Soft drinks and caffeine can result in high phosphorus levels, causing calcium to be drawn from the bones. Tobacco decreases estrogen effects, which in turn reduces the f bone mineralization. Progesterone in the presence of adequate estrogen stimulates bone formation. All menopausal and premenopausal women undergoing extreme endurance may have reduced estrogen production leading to decreased protective effects on bone metabolism. Alcohol can decrease healthy nutrition choices. Scoliosis, many endocrine diseases, exogenous glucocorticoids, other hypogonadal states and heavy metal exposure all can affect bone and increase fracture risk. Many women have lifestyles characterized by low dietary calcium and Vitamin D intake, low BM < 21, inactivity and/or no weightbearing activities.

The American Heart Association publishes evidence-based guidelines regarding the burden of vascular disease. Every 25 seconds an American has a coronary event and approximately every minute someone will die of an event. This is one of every six deaths in the United States! Mortality from stroke is one of every 18 deaths in the U.S. That translates into a stroke every 40 seconds. While rates of CVD death have declined, the burden of the CVD disease remains very high.

The National Osteoporosis Foundation (NOF) likewise reports that 25 million Americans have osteoporosis. American Society of Bone and Mineral Research and the NOF have guidelines for the screening, prevention and treatment of this silent disease. One in two women and one in three men will eventually have a fragility fracture. One in three women over age 50 has osteoporosis and one in twelve men has it. Eighty percent of fragility fractures however, happen to women, 250,000 hip fractures are reported annually, and there are 700,000 vertebral fractures and 250,000 wrist fractures. The FRAX (Fracture Risk Assessment Tool) designed by the World Health Organization and the National Osteoporosis Foundation provides a 10-year risk score. This screening is supported by the U.S. Preventive Safety Task Force. We encourage all practitioners to use it, just as we encourage all practitioners to use Framingham risk scoring and Reynold's risk scoring for women.

The risk factors for cardiovascular diseases are hypertension, high blood pressure, diabetes, cigarette smoking, overweight and obesity, poor diet, physical inactivity, alcohol use, family history, gender and age. Osteoporosis has many common risk factors similar to risk factors for cardiovascular disease. Both osteoporosis and heart disease are silent killers without signs or symptoms. A patient's first symptom is often a dramatic event, a fracture or a vascular event. Almost two-thirds of women who die suddenly of coronary heart disease have no symptoms. The challenge is to identify who is at risk and to screen, diagnose and treat in order to prevent additional disease burden.

Many Americans overdose with supplements under the misperception that this is a prescription for better health. The potential for side effects is often ignored.

Until evidence is solid, it is our belief that calcium supplements should be taken only with caution and according to professional guidelines.

Medline Plus and Consumer Reports are excellent evidence-based references with consumer information readily understood for the use of common supplements. The information is frequently updated. Impaired renal function, kidney stones, and gut and abdominal symptoms are common calcium usage concerns. Taking calcium throughout the day enhances absorption, and not taking a large dose will prevent a calcium spike. Calcium supplements do not reproduce the same metabolic effects as calcium-rich foods.

The U.S. Food and Drug Administration is conducting a safety analysis on calcium supplements.

Julie Paik, MD, of Harvard Medical School reported on an analysis from the Nurses' Health Study at the recent annual meeting of the American Society for Bone and Mineral Research. Their analysis was based on outcomes for 74,272 women who completed a food questionnaire in 1984. The participants were free of cardiovascular disease and cancer at the baseline. Dr. Paik reported that, in looking at outcomes for women who took more than 1000 mg calcium each day (the common dose that has been used in many of the trials included in the meta-analysis), no significant risks were identified, nor were any associations seen for stroke subtypes.

My current advice to women is to ingest 1000-1200 mg calcium daily, in a balanced nutritional diet. I suggest they take in adequate Vitamin D, and that they participate in weight-bearing exercises. The goal is to empower women to improve their lifestyles and to recognize and modify risk factors for both of these prevalent conditions. Vascular disease and osteoporosis are, for the most part, entirely preventable.

Disclosure statement: Dr. Maxson has no disclosures to report.